Migraine Headache Day (MHD):A calendar day on which a migraine headache or probable migraine headache occurred.

Migraine Headache : A headache, with or without aura, of ≥30 minutes duration with both of the following required features (A and B):

A) At least 2 of the following headache characteristics: Unilateral location; Pulsatile quality; Moderate or severe pain intensity; Aggravation by or causing avoidance of routine physical activity; AND B) During headache at least one of the following: Nausea and/or vomiting; Photophobia and phonophobia;

Overall mean is derived from the average of months 1 to 6 from mixed model repeated measures (MMRM) model. Least Square (LS) mean was calculated using mixed model repeated measures (MMRM) model with treatment, pooled country, month, and treatment by month, baseline, and baseline by month as fixed effects.

All randomized participants who received at least one dose of study drug and had baseline and at least one post baseline value.

Migraine Headache Day (MHD): A calendar day on which a migraine headache or probable migraine headache occurred.

Mean is derived from the average of months 1 to 6 from generalized linear mixed model repeated measures. Mean percentages of participants were calculated with a generalized linear mixed model repeated measures method with treatment, month and treatment by month, baseline.

All randomized participants who received at least one dose of study drug and had baseline and at least one post baseline value.

MSQ v2.1 was developed to address physical & emotional limitations of specific concern to individuals with migraine.

It consists of 14 items that address 3 domains:(1) Role Function-Restrictive (items 1-7);(2) Role Function- Preventive (items 8-11);&(3) Emotional Function (items 12-14).Response options range from "none of the time" (value 1) to "all of the time" (value 6), & are reverse-recoded (value 6 to 1) before the domain scores are calculated.Total raw scores for each domain is the sum of the final item value for all of the items in that domain.After the total raw score is computed for each domain, they are transformed to a 0-100 scale with higher scores indicating a better health status & a positive change in scores reflecting functional improvement.

Mean is derived from the average of months 4 to 6 from MMRM model. LSMean was calculated using MMRM model with treatment, pooled country, month, treatment by month, baseline by month & baseline MHD category as fixed factors.

All randomized participants who received at least one dose of study drug and had baseline and at least one post baseline value.

Migraine Headache Day (MHD):A calendar day on which a migraine headache or probable migraine headache occurred.

Overall mean is derived from the average of months 1 to 6 from MMRM model. LSMean was calculated using MMRM model with treatment, pooled country, month, treatment by month, baseline, baseline by month, and baseline MHD category as fixed effects.

All randomized participants who received at least one dose of study drug and had baseline and post baseline value.

The PGI-S scale is a patient-rated instrument that measures patients own global impression of their illness severity. The patient was instructed as follows: "Considering migraine as a chronic condition, how would you rate your level of illness?" Response options were from 1 ("normal, not at all ill") to 7 ("extremely ill"). Mean is derived from the average of months 4 to 6 from MMRM model. LSMean was calculated using MMRM model with treatment, pooled country, month, treatment by month, baseline, baseline by month, and baseline MHD category as fixed factors.

All randomized participants who received at least one dose of study drug and had baseline and post baseline value.

Headache Hours is calculated as the total number of headache hours on which a headache occurred. Overall mean is derived from the average of months 1 to 6 from MMRM model. LSMean was calculated using MMRM model with treatment, pooled country, month, treatment by month, baseline, baseline by month and baseline MHD category.

All randomized participants who received at least one dose of study drug and had baseline and at least one post baseline value.

The MIDAS is a participant-rated scale which was designed to quantify headache-related disability over a 3-month period. This instrument consists of five items that reflect the number of days reported as missing or with reduced productivity at work or home, and the number of days of missed social events. Each item has a numeric response range from 0 to 90 days, if days are missed from work or home they are not counted as days with reduced productivity at work or home. The numeric responses are summed to produce a total score ranging from 0 to 270, in which a higher value is indicative of more disability.

LSMean was calculated using MMRM model with treatment, pooled country, month, treatment by month, baseline, baseline by month, and baseline MHD category as fixed factors.

All randomized participants who received at least one dose of study drug and had baseline and at least one post baseline value.

Treatment emergent (TE) ADA evaluable participant is considered to be TE ADA+ if the subject has at least one post-baseline titer that is a 4-fold or greater increase in titer from baseline measurement. If baseline result is ADA Not Present, then the participant is TE ADA+ if there is at least one post-baseline result of ADA present with titer >= 1: 20.

All randomized participants who received at least one dose of study drug and had least one non-missing test result for ADA for each of the baseline period and the post-baseline period.

Pharmacokinetics (PK): Serum Concentrations of Galcanezumab.

All randomized participants who received at least one dose of study drug and had measurable serum concentrations.

Plasma Concentration of Calcitonin Gene-Related Peptide (CGRP).

All randomized participants who had received at least one dose of study drug and had measurable plasma concentrations.